Will do a Push without -f by default and if it fails as new branches would be
created in the target repo, warn the user
and give them the option to do a forced push if the really want to.

Created an attachment (id=54953) [details]
Proposed patch

IDE:-------------------------------------------------
IDE: [11/01/08 15:21] Committing started
Checking in ui/push/PushAction.java;
/shared/data/ccvs/repository/versioncontrol/mercurial/src/org/netbeans/modules/mercurial/ui/push/PushAction.java,v
 <--
 PushAction.java
new revision: 1.19; previous revision: 1.18
done
Please verify that this works against your remote repository - I've checked it
locally.

Checking in ui/push/Bundle.properties;
/shared/data/ccvs/repository/versioncontrol/mercurial/src/org/netbeans/modules/mercurial/ui/push/Bundle.properties,v 
<--  Bundle.properties
new revision: 1.12; previous revision: 1.11
done
Checking in util/HgCommand.java;
/shared/data/ccvs/repository/versioncontrol/mercurial/src/org/netbeans/modules/mercurial/util/HgCommand.java,v
 <-- 
HgCommand.java
new revision: 1.65; previous revision: 1.64
done
IDE: [11/01/08 15:21] Committing finished

If new branches would be created in the target repo, the correct response is
not to push -f! You should pull -u, merge,
commit, push again.

Why? If I am doing a push to a repo I am working with and I want to create the
new branch then surely that's my choice. 
We inform the user what will happen and let them make the call. If they don't
want to brnach, cancel and then go and do
a Pull. Otherwise continue with the Push.

That's why the dialog warns users and asks them if they had forgotten to sync
and merge first, giving them the option to
cancel.

If we don't give them the option then I can't push back to the repo and branch
it if I wish to.

Generally you do not want to create a new head in the public repository as this
simply forces someone else to do your
merge for you. (For NB repositories we may well enforce this with a server hook
rejecting any set of changesets which
introduces an extra head.) If you really wanted a new branch, you probably
meant to create a separate clone.

It is better than nothing to inform people with a dialog box that they need to
pull, but what a GUI should really do is
ask for permission and then go ahead and pull and merge and retry the push. It
should certainly not encourage a push -f
or make it seem easier than the correct alternative. IMHO a GUI should not
offer push -f as an option at all; if you
really know what you are doing and are sure you want to do it, you can always
push -f from the command-line.

OK - removed ability to do the forced push, now simply warn user that resync is
required and they need to do a Pull
followed by a Merge, before redoing the Push.

I have not added an option to do the Pull and Merge automatically, if you want
this then just raise an RFE, but it's
pretty easy for the user to do it themselves, using the available menus.

IDE:-------------------------------------------------
IDE: [15/01/08 13:39] Committing started
Checking in PushAction.java;
/shared/data/ccvs/repository/versioncontrol/mercurial/src/org/netbeans/modules/mercurial/ui/push/PushAction.java,v
 <--
 PushAction.java
new revision: 1.20; previous revision: 1.19
done
Checking in Bundle.properties;
/shared/data/ccvs/repository/versioncontrol/mercurial/src/org/netbeans/modules/mercurial/ui/push/Bundle.properties,v 
<--  Bundle.properties
new revision: 1.13; previous revision: 1.12
done
IDE: [15/01/08 13:39] Committing finished
IDE: [15/01/08 13:39] Diffing finished

Verified.

See issue #125704 for pull-and-merge ("fetch") combo.